1 files changed, 62 insertions, 88 deletions

diff --git a/Python/symtable.c b/Python/symtable.c
index 5eff364439..a0bedfc767 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -185,6 +185,7 @@ static int symtable_visit_params(struct symtable *st, asdl_seq *args);
 static int symtable_visit_argannotations(struct symtable *st, asdl_seq *args);
 static int symtable_implicit_arg(struct symtable *st, int pos);
 static int symtable_visit_annotations(struct symtable *st, stmt_ty s);
+static int symtable_visit_withitem(struct symtable *st, withitem_ty item);
 
 
 static identifier top = NULL, lambda = NULL, genexpr = NULL,
@@ -224,10 +225,17 @@ symtable_new(void)
 struct symtable *
 PySymtable_Build(mod_ty mod, const char *filename, PyFutureFeatures *future)
 {
-    struct symtable *st = symtable_new();
+    struct symtable *st;
     asdl_seq *seq;
     int i;
 
+    if (__class__ == NULL) {
+        __class__ = PyUnicode_InternFromString("@__class__");
+        if (__class__ == NULL)
+            return NULL;
+    }
+
+    st = symtable_new();
     if (st == NULL)
         return st;
     st->st_filename = filename;
@@ -743,14 +751,12 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
     }
     else {
         /* Special-case __class__ */
-        if (!GET_IDENTIFIER(__class__))
-            goto error;
         assert(PySet_Contains(local, __class__) == 1);
         if (PySet_Add(newbound, __class__) < 0)
             goto error;
     }
 
-    /* Recursively call analyze_block() on each child block.
+    /* Recursively call analyze_child_block() on each child block.
 
        newbound, newglobal now contain the names visible in
        nested blocks.  The free variables in the children will
@@ -782,7 +788,7 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
                                                          NULL))
         goto error;
     else if (ste->ste_type == ClassBlock && !analyze_cells(scopes, newfree,
-                                                           "__class__"))
+                                                           "@__class__"))
         goto error;
     /* Records the results of the analysis in the symbol table entry */
     if (!update_symbols(ste->ste_symbols, scopes, bound, newfree,
@@ -893,18 +899,15 @@ symtable_warn(struct symtable *st, char *msg, int lineno)
 static int
 symtable_exit_block(struct symtable *st, void *ast)
 {
-    Py_ssize_t end;
-
-    Py_CLEAR(st->st_cur);
-    end = PyList_GET_SIZE(st->st_stack) - 1;
-    if (end >= 0) {
-        st->st_cur = (PySTEntryObject *)PyList_GET_ITEM(st->st_stack,
-                                                        end);
-        if (st->st_cur == NULL)
-            return 0;
-        Py_INCREF(st->st_cur);
-        if (PySequence_DelItem(st->st_stack, end) < 0)
+    Py_ssize_t size;
+
+    st->st_cur = NULL;
+    size = PyList_GET_SIZE(st->st_stack);
+    if (size) {
+        if (PyList_SetSlice(st->st_stack, size - 1, size, NULL) < 0)
             return 0;
+        if (--size)
+            st->st_cur = (PySTEntryObject *)PyList_GET_ITEM(st->st_stack, size - 1);
     }
     return 1;
 }
@@ -913,23 +916,23 @@ static int
 symtable_enter_block(struct symtable *st, identifier name, _Py_block_ty block,
                      void *ast, int lineno, int col_offset)
 {
-    PySTEntryObject *prev = NULL;
+    PySTEntryObject *prev = NULL, *ste;
 
-    if (st->st_cur) {
-        prev = st->st_cur;
-        if (PyList_Append(st->st_stack, (PyObject *)st->st_cur) < 0) {
-            return 0;
-        }
-        Py_DECREF(st->st_cur);
-    }
-    st->st_cur = ste_new(st, name, block, ast, lineno, col_offset);
-    if (st->st_cur == NULL)
+    ste = ste_new(st, name, block, ast, lineno, col_offset);
+    if (ste == NULL)
         return 0;
+    if (PyList_Append(st->st_stack, (PyObject *)ste) < 0) {
+        Py_DECREF(ste);
+        return 0;
+    }
+    prev = st->st_cur;
+    /* The entry is owned by the stack. Borrow it for st_cur. */
+    Py_DECREF(ste);
+    st->st_cur = ste;
     if (block == ModuleBlock)
         st->st_global = st->st_cur->ste_symbols;
     if (prev) {
-        if (PyList_Append(prev->ste_children,
-                          (PyObject *)st->st_cur) < 0) {
+        if (PyList_Append(prev->ste_children, (PyObject *)ste) < 0) {
             return 0;
         }
     }
@@ -1023,12 +1026,6 @@ error:
     if (!symtable_visit_ ## TYPE((ST), (V))) \
         return 0;
 
-#define VISIT_IN_BLOCK(ST, TYPE, V, S) \
-    if (!symtable_visit_ ## TYPE((ST), (V))) { \
-        symtable_exit_block((ST), (S)); \
-        return 0; \
-    }
-
 #define VISIT_SEQ(ST, TYPE, SEQ) { \
     int i; \
     asdl_seq *seq = (SEQ); /* avoid variable capture */ \
@@ -1039,18 +1036,6 @@ error:
     } \
 }
 
-#define VISIT_SEQ_IN_BLOCK(ST, TYPE, SEQ, S) { \
-    int i; \
-    asdl_seq *seq = (SEQ); /* avoid variable capture */ \
-    for (i = 0; i < asdl_seq_LEN(seq); i++) { \
-        TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
-        if (!symtable_visit_ ## TYPE((ST), elt)) { \
-            symtable_exit_block((ST), (S)); \
-            return 0; \
-        } \
-    } \
-}
-
 #define VISIT_SEQ_TAIL(ST, TYPE, SEQ, START) { \
     int i; \
     asdl_seq *seq = (SEQ); /* avoid variable capture */ \
@@ -1061,18 +1046,6 @@ error:
     } \
 }
 
-#define VISIT_SEQ_TAIL_IN_BLOCK(ST, TYPE, SEQ, START, S) { \
-    int i; \
-    asdl_seq *seq = (SEQ); /* avoid variable capture */ \
-    for (i = (START); i < asdl_seq_LEN(seq); i++) { \
-        TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, i); \
-        if (!symtable_visit_ ## TYPE((ST), elt)) { \
-            symtable_exit_block((ST), (S)); \
-            return 0; \
-        } \
-    } \
-}
-
 #define VISIT_KWONLYDEFAULTS(ST, KW_DEFAULTS) { \
     int i = 0; \
     asdl_seq *seq = (KW_DEFAULTS); /* avoid variable capture */ \
@@ -1122,8 +1095,8 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s)
                                   FunctionBlock, (void *)s, s->lineno,
                                   s->col_offset))
             return 0;
-        VISIT_IN_BLOCK(st, arguments, s->v.FunctionDef.args, s);
-        VISIT_SEQ_IN_BLOCK(st, stmt, s->v.FunctionDef.body, s);
+        VISIT(st, arguments, s->v.FunctionDef.args);
+        VISIT_SEQ(st, stmt, s->v.FunctionDef.body);
         if (!symtable_exit_block(st, s))
             return 0;
         break;
@@ -1142,8 +1115,7 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s)
         if (!symtable_enter_block(st, s->v.ClassDef.name, ClassBlock,
                                   (void *)s, s->lineno, s->col_offset))
             return 0;
-        if (!GET_IDENTIFIER(__class__) ||
-            !symtable_add_def(st, __class__, DEF_LOCAL) ||
+        if (!symtable_add_def(st, __class__, DEF_LOCAL) ||
             !GET_IDENTIFIER(__locals__) ||
             !symtable_add_def(st, __locals__, DEF_PARAM)) {
             symtable_exit_block(st, s);
@@ -1151,7 +1123,7 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s)
         }
         tmp = st->st_private;
         st->st_private = s->v.ClassDef.name;
-        VISIT_SEQ_IN_BLOCK(st, stmt, s->v.ClassDef.body, s);
+        VISIT_SEQ(st, stmt, s->v.ClassDef.body);
         st->st_private = tmp;
         if (!symtable_exit_block(st, s))
             return 0;
@@ -1205,19 +1177,16 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s)
     case Raise_kind:
         if (s->v.Raise.exc) {
             VISIT(st, expr, s->v.Raise.exc);
-        if (s->v.Raise.cause) {
-        VISIT(st, expr, s->v.Raise.cause);
-        }
+            if (s->v.Raise.cause) {
+                VISIT(st, expr, s->v.Raise.cause);
+            }
         }
         break;
-    case TryExcept_kind:
-        VISIT_SEQ(st, stmt, s->v.TryExcept.body);
-        VISIT_SEQ(st, stmt, s->v.TryExcept.orelse);
-        VISIT_SEQ(st, excepthandler, s->v.TryExcept.handlers);
-        break;
-    case TryFinally_kind:
-        VISIT_SEQ(st, stmt, s->v.TryFinally.body);
-        VISIT_SEQ(st, stmt, s->v.TryFinally.finalbody);
+    case Try_kind:
+        VISIT_SEQ(st, stmt, s->v.Try.body);
+        VISIT_SEQ(st, stmt, s->v.Try.orelse);
+        VISIT_SEQ(st, excepthandler, s->v.Try.handlers);
+        VISIT_SEQ(st, stmt, s->v.Try.finalbody);
         break;
     case Assert_kind:
         VISIT(st, expr, s->v.Assert.test);
@@ -1305,10 +1274,7 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s)
         /* nothing to do here */
         break;
     case With_kind:
-        VISIT(st, expr, s->v.With.context_expr);
-        if (s->v.With.optional_vars) {
-            VISIT(st, expr, s->v.With.optional_vars);
-        }
+        VISIT_SEQ(st, withitem, s->v.With.items);
         VISIT_SEQ(st, stmt, s->v.With.body);
         break;
     }
@@ -1338,8 +1304,8 @@ symtable_visit_expr(struct symtable *st, expr_ty e)
                                   FunctionBlock, (void *)e, e->lineno,
                                   e->col_offset))
             return 0;
-        VISIT_IN_BLOCK(st, arguments, e->v.Lambda.args, (void*)e);
-        VISIT_IN_BLOCK(st, expr, e->v.Lambda.body, (void*)e);
+        VISIT(st, arguments, e->v.Lambda.args);
+        VISIT(st, expr, e->v.Lambda.body);
         if (!symtable_exit_block(st, (void *)e))
             return 0;
         break;
@@ -1422,8 +1388,7 @@ symtable_visit_expr(struct symtable *st, expr_ty e)
         if (e->v.Name.ctx == Load &&
             st->st_cur->ste_type == FunctionBlock &&
             !PyUnicode_CompareWithASCIIString(e->v.Name.id, "super")) {
-            if (!GET_IDENTIFIER(__class__) ||
-                !symtable_add_def(st, __class__, USE))
+            if (!symtable_add_def(st, __class__, USE))
                 return 0;
         }
         break;
@@ -1540,6 +1505,16 @@ symtable_visit_excepthandler(struct symtable *st, excepthandler_ty eh)
     return 1;
 }
 
+static int
+symtable_visit_withitem(struct symtable *st, withitem_ty item)
+{
+    VISIT(st, expr, item->context_expr);
+    if (item->optional_vars) {
+        VISIT(st, expr, item->optional_vars);
+    }
+    return 1;
+}
+
 
 static int
 symtable_visit_alias(struct symtable *st, alias_ty a)
@@ -1650,13 +1625,12 @@ symtable_handle_comprehension(struct symtable *st, expr_ty e,
         symtable_exit_block(st, (void *)e);
         return 0;
     }
-    VISIT_IN_BLOCK(st, expr, outermost->target, (void*)e);
-    VISIT_SEQ_IN_BLOCK(st, expr, outermost->ifs, (void*)e);
-    VISIT_SEQ_TAIL_IN_BLOCK(st, comprehension,
-                            generators, 1, (void*)e);
+    VISIT(st, expr, outermost->target);
+    VISIT_SEQ(st, expr, outermost->ifs);
+    VISIT_SEQ_TAIL(st, comprehension, generators, 1);
     if (value)
-        VISIT_IN_BLOCK(st, expr, value, (void*)e);
-    VISIT_IN_BLOCK(st, expr, elt, (void*)e);
+        VISIT(st, expr, value);
+    VISIT(st, expr, elt);
     return symtable_exit_block(st, (void *)e);
 }